Attempts have been made to reduce the thickness of cans in order to save natural resources and reduce cost, and various can shapes have been suggested to compensate for the decrease in can strength which accompanies such thickness reduction. In particular, the shape of a can bottom is generally known in which a dome part having a center that is recessed in a dome—like shape to the inner side is provided and a leg part projecting annularly downward of a can axis is provided around the dome part in order to increase the internal pressure resistance.
Further, in a can body to be filled with contents, such as carbonated beverages, that increase the internal pressure, molding which is called bottom reforming is generally performed by recessing an inner side connection portion of the leg part and the dome part toward the outer side of the leg part in order to further increase the internal pressure resistance (for example, see Patent Documents 1 and 2 shown below).